12.3.1 Footnote Commands

In Texinfo, footnotes are created with the @footnote command.
This command is followed immediately by a left brace, then by the text
of the footnote, and then by a terminating right brace. Footnotes may
be of any length (they will be broken across pages if necessary), but
are usually short. The template is:

ordinary text@footnote{text of footnote}

As shown here, the @footnote command should come right after the
text being footnoted, with no intervening space; otherwise, the footnote
marker might end up starting a line.

For example, this clause is followed by a sample footnote5; in the Texinfo source, it looks like
this:

…a sample footnote@footnote{Here is the sample
footnote.}; in the Texinfo source…

As you can see, this source includes two punctuation marks next to
each other; in this case, ‘.};’ is the sequence. This is normal
(the first ends the footnote and the second belongs to the sentence
being footnoted), so don’t worry that it looks odd. (Another style,
perfectly acceptable, is to put the footnote after punctuation
belonging to the sentence, as in ‘;@footnote{...’.)

In a printed manual or book, the reference mark for a footnote is a
small, superscripted number; the text of the footnote appears at the
bottom of the page, below a horizontal line.

In Info, the reference mark for a footnote is a pair of parentheses
with the footnote number between them, like this: ‘(1)’. The
reference mark is followed by a cross reference link to the footnote
text if footnotes are put in separate nodes (see Footnote Styles).

In the HTML output, footnote references are generally marked with a
small, superscripted number which is rendered as a hypertext link to
the footnote text.

Footnotes cannot be nested, and cannot appear in section headings of
any kind or other “unusual” places.

A final tip: footnotes in the argument of an @item command for
an @table must be entirely on the same line as the
@item (as usual). See Two-column Tables.